The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Ultrasound imaging systems have a probe for transmitting an ultrasound wave signal to an object in contact with the probe and receiving a reflected ultrasound wave signal (hereinafter called echo) from the object to form and present an ultrasound image on a display based on the received echo signal. The ultrasound image is mainly represented by a brightness-mode (B-mode) using a reflection coefficient depending on the difference in acoustic impedance between different tissues. Besides the B-mode, the ultrasound image has a C-mode that is a color flow image mode or and a BC-mode which provides both of the B-mode and the C-mode for showing the state of blood flows or movements of the object by using Doppler effect.
Meanwhile, treatment procedures such as an examination, biopsy and surgery require an accurate inspection of a patient's lesion or tissue, which may require ultrasound imaging systems to obtain a multifocal ultrasound image. However, acquiring the multifocal ultrasound image may accompany a significant reduction of the frame rate of the ultrasound image provided by the ultrasound imaging system. With a view to increasing the frame rate, some approach decreases the line density. For example, such approach performs only 64 transmissions even with a 128-element probe instead of normal 128 transmissions. However, this scheme will bring a lowered resolution in spite of the doubled frame rate.
Further, the C-mode contains directionality information of data, and applying a linear interpolation to the directional data incurs an interpolation error associated with the directionality.